When to Plant Freesia in King County, WA
Top priorities for King County, Washington gardeners in June
Here's what deserves your attention in King County, Washington this month. Everything below is tailored to Zone 9a and timed around your local frost dates.
Freesias (Freesia spp.) are prized above almost all other cut flowers for their intense, sweet fragrance — a single stem can fill a room. Slender, arching stems carry one-sided sprays of funnel-shaped flowers in white, yellow, pink, orange, red, purple, and lavender. Native to South Africa's Cape region, freesias thrive in cool, mild weather and go dormant in summer heat, making them ideal for mild-winter climates where they bloom in late winter through spring. The 'Marilyn', 'Blue Heaven', and 'Yellow Rivers' cultivars are staples of the commercial cut flower trade.
King County, Washington is in USDA Zone 9a. The average last spring frost is April 7 and the first fall frost is October 30, giving you a growing season of approximately 206 days.
At an elevation of 258 feet, King County receives approximately 37.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Freesia during the growing season.
King County Soil Profile
Soil Type
Silt Loam
Soil pH
5.7-6.4
Drainage
Well Drained
Freesia Planting Risk Windows
Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.
Soil Compatibility in King County
How your county's soil matches Freesia's growing requirements.
Soil pH
Your soil pH (5.7–6.4) overlaps with Freesia's range (6.0–7.0), though not a perfect match.
Soil Texture
The silt loam soil in King County is excellent for Freesia — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is excellent (5.5%) — Freesia will thrive.
How to Plant Freesia
Fall planting: Sow 6 weeks before your first frost date for a fall harvest.
Freesia Water Budget
Monthly Watering Guide for Freesia
Freesia needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Freesia Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 5.9" | 0" | ❄️ Dormant |
| Feb | — | 4.5" | 0" | ❄️ Dormant |
| Mar | — | 3.4" | 0" | ❄️ Dormant |
| Apr | 4.3" | 2.9" | 1.4" | 💧 Light watering |
| May | 4.3" | 2" | 2.3" | 🚿 Regular watering |
| Jun | 4.3" | 1.3" | 3" | 🚿 Regular watering |
| Jul | 4.3" | 0.6" | 3.7" | 🚿 Regular watering |
| Aug | 4.3" | 0.7" | 3.6" | 🚿 Regular watering |
| Sep | 4.3" | 1.6" | 2.7" | 🚿 Regular watering |
| Oct | 4.3" | 3.4" | 0.9" | 💧 Light watering |
| Nov | — | 5.6" | 0" | ❄️ Dormant |
| Dec | — | 5.7" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Oct in King County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Freesia Heat Requirements (GDD)
What are Growing Degree Days (GDD)?
Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.
Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.
Freesia Planting Timeline — King County, WA
Freesia Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Bloom | October 2 | Oct 2 – Oct 30 |
| Fall Sowing | September 18 | Sep 18 – Oct 2 |
Plant 2" deep · 3" apart · Rows 4" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | — |
| February | — |
| March | — |
| April | — |
| May | — |
| June | — |
| July | — |
| August | — |
| September | Fall Sowing |
| October | Fall Sowing Bloom |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · Only during dry spells
📅 Days to Maturity
84–112 days
🧪 Soil pH
Needs 6–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 9a
📆 Growing Season
206 days in King County
Growing Tips for Freesia in King County
Direct sow Freesia outdoors after April 07 in King County when soil has warmed and frost danger has passed.
General growing tips
Plant corms 2 inches deep with the pointed end up, 2–3 inches apart, in autumn (September–November in zones 8–10). Full sun and excellent drainage are essential — freesias rot in soggy soil. They need cool but frost-free growing conditions (40–60°F nights) to initiate flower buds; warm nights above 70°F suppress bloom. In zones 8–9, provide a winter mulch if hard frost threatens. After flowering, allow foliage to yellow and die back naturally; this ripens the corm for the following year. In zones 8a–9b, corms may multiply and naturalize over time but perform best when replanted fresh each fall. In zones 10–11, plant from October through December for a January–April bloom. Freesias are toxic to cats and dogs.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Freesia in Other Locations
Frequently Asked Questions
When should I plant Freesia in King County, WA?
King County is in Zone 9a with an average last frost of April 7. Plan your Freesia planting based on this frost date — see the calendar above for exact timing.
What planting zone is King County, WA?
King County, Washington is in USDA Hardiness Zone 9a. The average last spring frost is April 7 and first fall frost is October 30.
Your King County Garden Planner — Free
A 22-page printable planner built for King County (Zone 9a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.